William bedford mttlock



W. R. MULOCK.

NOISE REDUCING TYPEWRITER PLATEN.

APPLICATION FILED DEC. l5. |920.

Patend June 21, 1921.

UNITED STATES PATENT- OFFICE.

NOISE-BEDUCING TYPEWEITER-PLATEN.

Specification of Letters Patent.

Patented June 21, 1921.

Application led December 15, 1920. Serial No. 431,014.

To all whom it may concern:

Be it known that I, WILLIAM BEDFORD MULocK, a subject of the King of Great Britain, and resident of Winnipeg, in the Province of Manitoba, Dominion of Canada, have invented certain new and useful Improvements in Noise-Reducing Typewriter- Platens, of which the following is a full, clear, and exact specification.

This invention relates to platens for typewriting machines, and has for its object to provide an improved form of platen which may be substituted for that now in general use and which will greatly reduce the noise caused by the type striking the platens now in common use.

The present invention contemplates the use of a non-rotating skeleton cylindrical platen frame provided with a cushioned striking or platen strip which does not revolve, and a pluralit of paper-feeding rollers in the platen apted to be simultaneously rotated for moving the paper over said Striking Strip and between it and the ribbon. The skeleton platen, carrying the striking strip and paper-feeding rollers, is to be reciprocated as and interchangeable with the ordinary platen on the carriage of a typewriting machine but will be secured so as not to rotate.

The invention will be first hereinafter described in connection with the accompanying drawings, which constitute part of this specification, and then more specifically defined in the claims at the end of the description.

In the accompanying drawings, wherein similar reference characters are used to designate corresponding parts throughout the several views Figure 1 is a plan view of a platen constructed substantially in accordance with this invention.

Fig. 2 is central longitudinal section thereof.

Fig. 3 is a cross section on the line III-III of Fig. 2 showing a part of a typewriter carriage in dotted lines.

Fig. 4 is a section on the line IV-IV of Fig: 2.

ig. 5 is a detailed sectional view of the cushloned striking strip showing more clearly how it is maintained in proper alinement.

Fig. 6 is a front elevation of the right hand end portion of the casing showing the screw pins 3, 3, and the bar of the carriage engaged thereby, said bar and the carriage being shown in dotted lines.

The carriage of a typewriting machine is indicated in a general way in dotted lines at 1 in Fig. 3 of the drawings, and my improved platen is supported thereon in the same manner as the ordinary roller platen, but is secured against rotation in any suitable manner, as by the pair of screw pins 3 at each end arranged at opposite sides of a fixed bar 4 of the carriage 1, as is more clearly seen in Fig. 6. The platen may be of any Ordinar or desired length, as indicated by breaklng away its middle portion in Figs. 1 and 2.

The laten frame may have end disks 5 which t inside of the ends of the skeleton casing 6 and to which they are fastened. A central shaft 7 extends rotatably through the centers of the end disks and has milled caps 8 on its opposite ends for turning said shaft by hand. The area of the skeleton casing 6 is reduced as much as possible in order that there may be less material in it to produce sound from the striking of the type. Said casing has a slot 8a extending horizontally substantially from end to en-d thereof in its front portion. In this slot there is arranged a striking or platen strip 9 which substantially fills said slot and is maintained in proper alinement therein in any suitable manner, preferably by a rubber strip 24 (as in Fig. 5) along the casing on the lower edge of the said slot on which it will rest. The strip 9 may be of rubber or any other suitable material, and it is preferably set in a clip 10 and cushioned on springs 11 supported on a sleeve 12 loosely mounted on the center shaft 7, as best shown in Fig. 5, but any other means for cushioning the strip 9 may be employed without affecting the principle of this invention.

Journaled in the end disks 5 of the platen are a plurality of paper-feeding rollers 13 of any necessary or desirable length and diameter. Three such rollers are illustrated,

one being arranged at the back of the platen and the other two above and below the platen strip 9, respectively, but the number and positions of these paper-feeding rollers may be changed if desired to suit diderent kinds of typewriting machinesa Each roller 13 preferably has its paper-engaging surface made of rubber le@ and arranged to project slightly beyond the surface of the platen `easing so as to engage the paper 15, llig. 3,

and carry it around the platen between the striking strip and the ribbon which is indicated at 22 in said ligure. lVhen the'platen is in use on the carriage of a typewriting machine, the paper-holding rolleis 16 of said carriage will press the paper into frictional contact with the nlaten rollers, 13, as indicated in dotted lines in Fig. 3. y y

The rollers 13 extend through the right hand end disk 5 of theplaten and have gears 17 fixed thereon tomesh with an internal gear '18 on the inner face of an end member 19 which is fast on the center shaft 7 and also has the usual ratchet teeth 20 on its periphery for engagement with the pawl (not shown) which is ordinarily provided on a typewriting machine for inechanicallyregulating the feeding of the paper during the operation of the machine. By means of this construction, the rotation of the center shaft by said pawl or by the hands of the operator grasping one or both of the milled caps 8 willL simultaneously revolve all of the rollers 13 so as to feed the paper l5, Fig. 3, around the platen and across the striking or platen strip 9. v

@ne or more bars may be used along the topl of the platen between the end disks 5 to hold said platen rigid where the skeleton casing 6 is cut away. This bar will be `just above the roller w iich is above the narrow strip of the "asing which forms the upper edge of the slot 8 and it will take the paper as it cornes off the roller. Rubber washers and insulating strips (not shown) are usedv where possible in the construction of the platen with a view eliminating noise.

I" making form and reducing the Striking surface to a narrow cushioned strip the noise usually incident to the type striking the common hard roller platen is very greatly' reduced, and the provision of the simultaneously actuated paper-feeding rollers insures the even and true movement of the paper during` the operation of a typewriting machine equipped with the present invention. It will be understood that details of construction may be altered without departing from the spirit or sacriicing the advantages of the invention. y

Having thus described my invention, what I claim as new and desire to secure by liet ters Patent of the United States is:

1. In a typewriter platen frame, the cointhe platenframe in skeleton.

bination with a cushioned striking or platen strip secured against rotation, of a plurality of paper-feeding rollers mounted within said platen frame and arranged at intervals around its periphery yfor moving a sheet of paper across said striking or platen strip, and means kfor simultaneously actuating said rollers.

2. In a typewriter platen, the combina-l tion with a skeleton cylindrical platen frame secured against rotation and having a longitudinal space therein, of a striking or platen strip arranged insa-id space and cushioned to yield under the impact of the type, and cooperating papenfeeding rollers mounted in the platen frame to cooperate with the paper-feeding rollers of a typewriter carriage outside the periphery of said platen frame.

3. In a typewriter platen, the combination with a skeleton cylindrical platen frame secured against rotation and having an open longitudinal space therein, of a cushioned striking ,or platen strip arranged in said space, cooperating with paper-feeding rollers mounted in the platen frame, and means for simultaneously actuating all of said rollers.

4L. In a typewriter platen, the combination with a skeleton cylindrical platen frame secured against rotation, of a cushioned strik` ing or platen strip forming part thereof, a plurality of paper-feeding rollers mounted in the platen frame, gears on said rollers, and a master gear meshing with all of the gears on said rollers for simultaneously actuating said rollers.

5. vIn a typewriter platen, the combination with a skeleton cylindrical platen frame secured against rotation, of Va cushioned striking or platen strip forming part thereof, a plurality of paper-feeding rollers mounted in the platen frame, gears on said rollers, and an internal gear meshing with all of the gears on the rollers for simultaneously actuating said rollers..

6. In a typewriter platen, the combination with a skeleton cylindrical platen frame secured against rotation, of a cushioned .striking or pla-ten strip forming part thereof, a plurality of paper-feeding rollers mounted in the platen frame, gears on said rollers, a central shaft, a gear on said shaft, meshing with all of the gears on the rollers, and means for rotating said shaft and gear thereon for simultaneously actuating said rollers.

7. 4In a typewriter platen, the combina tion with a skeleton cylindrical platen frame secured against rotation, of a cushioned striking or platen strip forming part thereof, a plurality of' paper-feeding rollers mounted in the platen frame, gears on said rollers, an internal gear meshing with the gears on the rollers, and'means on the periphery of said internal gear for actuating tating the same, a striking or platen strip the same. also mounted in the casing, and cushioning 8. In a typewriter platen, the combination supports for said strip hung loosely on said 10 with a, skeleton cylindrical casing secured shaft. 5 against rotation, of paper-feeding rollers In testimony whereof I have signed my mounted in said casing, a revoluble shaft name to this s ecification. operatively connected to said rollers for ro- WILLIA REDFORD MULOCK. 

